On Thu, 2008-01-10 at 16:36 +0000, Ben Hutchings wrote:
> > When I run netperf in just one interface, I get 940.95 * 10^6 bits/sec
> > of transfer rate. If I run 4 netperf against 4 different interfaces, I
> > get around 720 * 10^6 bits/sec.
> <snip>
>
> I take it that's the average for individual interfaces, not the
> aggregate?
Right, each of these results are for individual interfaces. Otherwise,
we'd have a huge problem. :-)
> This can be mitigated by interrupt moderation and NAPI
> polling, jumbo frames (MTU >1500) and/or Large Receive Offload (LRO).
> I don't think e1000 hardware does LRO, but the driver could presumably
> be changed use Linux's software LRO.
Without using these "features" and keeping the MTU as 1500, do you think
we could get a better performance than this one?
I also tried to increase my interface MTU to 9000, but I am afraid that
netperf only transmits packets with less than 1500. Still investigating.
> single CPU this can become a bottleneck. Does the test system have
> multiple CPUs? Are IRQs for the multiple NICs balanced across
> multiple CPUs?
Yes, this machine has 8 ppc 1.9Ghz CPUs. And the IRQs are balanced
across the CPUs, as I see in /proc/interrupts:
# cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5
CPU6 CPU7
16: 940 760 1047 904 993 777
975 813 XICS Level IPI
18: 4 3 4 1 3 6
8 3 XICS Level hvc_console
19: 0 0 0 0 0 0
0 0 XICS Level RAS_EPOW
273: 10728 10850 10937 10833 10884 10788
10868 10776 XICS Level eth4
275: 0 0 0 0 0 0
0 0 XICS Level ehci_hcd:usb1, ohci_hcd:usb2, ohci_hcd:usb3
277: 234933 230275 229770 234048 235906 229858
229975 233859 XICS Level eth6
278: 266225 267606 262844 265985 268789 266869
263110 267422 XICS Level eth7
279: 893 919 857 909 867 917
894 881 XICS Level eth0
305: 439246 439117 438495 436072 438053 440111
438973 438951 XICS Level eth0 Neterion Xframe II 10GbE network
adapter
321: 3268 3088 3143 3113 3305 2982
3326 3084 XICS Level ipr
323: 268030 273207 269710 271338 270306 273258
270872 273281 XICS Level eth16
324: 215012 221102 219494 216732 216531 220460
219718 218654 XICS Level eth17
325: 7103 3580 7246 3475 7132 3394
7258 3435 XICS Level pata_pdc2027x
BAD: 4216
Thanks,
--
Breno Leitao <[EMAIL PROTECTED]>
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